There are thousands of amateur cricket teams in Britain, and not many have a book written about them. Still fewer have two or three, but this is what has happened to the Captain Scott Invitation XI, a wandering club formed by a gang of 1980s Oxford undergraduates whose wits were a lot sharper than their skills.

One of the founders was Marcus Berkmann, who became a comic writer. His book about the club, Rain Men (1995), is widely regarded as a classic of the genre. In fact, it defined the genre - the comic memoir of sporting incompetence - and sold so well that Berkmann wrote a sequel, Zimmer Men (2005). Another founder was Harry Thompson, who became a television comedy producer, novelist and biographer, and eventually wrote Penguins Stopped Play, about the club's attempt to play on every continent of the world. The Captain Scott XI is shaping up as club cricket's answer to the Bloomsbury group.

Best friends from the age of 10, both educated at Highgate and Oxford, both turning their comic gifts into careers and sharing the captaincy of their club, Thompson and Berkmann may strike the reader as virtual twins. They even wrote books together, churning out forgotten stocking-fillers that rejoiced in the titles of Fatties, Beardies and Baldies. But there is one crucial, brutal difference in the course of their lives. Thompson was diagnosed with inoperable lung cancer last spring and died in November, aged 45.

This book was thus a race against the ultimate deadline. Thompson opted to say very little about his predicament, showing admirable stoicism - Captain Scott with a hint of Captain Oates - but questionable literary judgment. It made it harder for his tale to shake off Berkmann's shadow.

Thompson's book does roam wider. When Berkmann left to start a splinter club, Thompson carried on captaining Captain Scott, so he has several more years of club memories to milk. And the world tour carries him away from the village greens of England to take in Singapore, Buenos Aires and Antarctica. Sketching each stop with deft relish, Thompson almost launches another genre - the picaresque comic memoir of sporting incompetence.

The problem is that one club cricket book turns out to be much like another. It's a collection of match reports and anecdotes - stag-night stuff, usually involving feckless team-mates, fearsome opponents, massive hangovers and blithe exaggeration - held together by a voice.

Not that the voice is bad. Thompson's prose is vividly conversational, rolling along with hardly a colon or semi-colon, and it can be very funny. It's also a close relative of Berkmann's style, which has all those qualities and more soul. One wonders if they have a common antecedent, a Highgate master with a weakness for cricket and a nonchalant turn of phrase.

The idea that clever men with better things to do devote their spare time to playing cricket, badly, has become familiar. More compelling is the idea that a man with months to live would spend his days writing about playing cricket badly. I kept wanting Thompson to explain why. I was also hoping he would go into his fractured friendship with Berkmann. There was clearly a falling-out: near the end, Thompson aims a cheap shot at Berkmann's new team, saying they stumped up only £20 for a memorial to a dead team-mate when the Scott XI had raised £500. But that's as open as the warfare gets.

Thompson begins by reflecting on Scott, fighting his unwinnable battle with Amundsen and the elements. He finishes by filling the reader in, briefly and dauntlessly, on his own unwinnable battle with illness, a task completed by an elegant afterword from his widow, Lisa, who married him on the day he died. The unwritten story is of a third unwinnable battle, the attempt to compete with his former friend. But a fourth battle, which could have been doomed too - to finish the book from his hospital bed - was triumphantly won. I ended up only half-enjoying the book, while marvelling that Thompson had managed to write it. In Rain Men, he appears as "an all-rounder of little obvious ability but frightening determination". That quality shines out like a light on a scoreboard.